The present invention relates to a device for use in fluid controllers, such as on-off valves, which are included, for example, in semiconductor manufacturing apparatus, the device being adapted to lock a channel opening-closing handle of the controller in a full opening or full closing position.
Fluid controllers are fully opened or fully closed as required by manipulating a channel opening-closing handle, whereas no device has been known for locking the handle in the full opening or closing position.
The conventional fluid controller therefore has the problem that the handle becomes shifted during the operation of the semiconductor manufacturing apparatus, failing to permit a proper flow of fluid to adversely affect the product.
An object of the present invention is to provide a device for locking the channel opening-closing handle of a fluid controller to eliminate errors involved in opening or closing the channel of the controller.
The present invention provides a device for locking a channel opening-closing handle of a fluid controller in a full opening or full closing position, the handle being rotatable relative to a body of the fluid controller, the locking device comprising a stopper support having a body fitting opening and fixed to the controller body, and a stopper nonrotatably provided on the stopper support and engageable with the handle for preventing the rotation of the handle.
The term the xe2x80x9cbody of a fluid controllerxe2x80x9d means the portion of the fluid controller which is fixed relative to the channel opening-closing handle which is rotatable. For example, when the controller has a valve case (body) having a channel and a valve closure (bonnet) covering and fixed to the valve case, the combination of these two components will be referred to as the controller body.
With the locking device of the present invention, the stopper engageable with the handle to prevent the rotation thereof is not rotatable relative to the stopper support which is fixed to the controller body. This eliminates the likelihood that the handle will shift inadvertently, consequently obviating the trouble that an improper flow of fluid will adversely affect the product.
According to an embodiment of the invention, the stopper support comprises a first member generally U-shaped and having a pair of side walls for holding therebetween two opposite flat faces of the controller body from opposite sides thereof, and a straight second member extending between and attached to free ends of the side walls for preventing the first member from slipping off the controller body, the stopper being integral with the first member. To provide this arrangement, the first member is mounted on the controller body, with the two side walls of the first member fitted to the respective flat faces of the body, whereby the first member is prevented from rotating relative to the controller body. The second member is then made to extend between and attached to the free ends of the side walls, whereby the first member is prevented from slipping off the controller body.
The second member is, for example, a pin having a head and insertable through an insertion bore formed in each of the two side walls of the U-shaped first member. A through bore is formed in the shank of the second member, such that one of the side walls is positionable between the head of the second member and the through bore thereof. The second member is passed through the insertion bore of one of the side walls and inserted through the insertion bore of the other side wall, and a lock is attached to the second member using the through bore. The second member is then prevented from slipping off by the lock and the head of the second member, consequently making it impossible to turn the handle unless the lock is undone. This eliminates any of the errors to be involved in opening or closing the channel of the fluid controller. Instead of using the lock, the insertion bore of one of the side walls may be in the form of a threaded bore, with an externally threaded portion formed at the forward end of the second member. The second member can then be prevented from slipping off when inserted through the insertion hole of the other side wall and screwed into the threaded bore of the above-mentioned side wall.
Preferably, the stopper is mounted on the stopper support so as to be movable upward and downward between a locking position in which the stopper engages with the handle and an unlocking position in which the stopper is out of engagement with the handle. The locking position or the unlocking position is then alternatively selectable merely by moving the stopper upward or downward, hence a facilitated change-over.
This can be realized by an arrangement wherein the stopper support is formed by a first member and a second member joined to each other, and each of the first and second members is formed with a recess and another recess for forming the body fitting opening and a stopper fitting aperture, respectively, when the two members are joined, the stopper having a vertical portion slidably fitted in the aperture and formed with a lock attaching bore.